Australia braced for more sweltering temperatures

With temperatures expected to hit the high 30s and low 40s in western NSW, western Sydney and the lower Blue Mountains over the weekend, emergency services are warning the public of a very high risk of bushfires.

Rural Fire Service Commissioner Shane Fitzsimmons said firefighters this year had already battled more than 3800 bush and grass fires and he is urging people to develop bushfire survival plans.

"This summer, complacency could kill, but preparation could save lives," he said.

A heatwave in Sydney in 2011 killed 96 people, NSW Health says.

Authorities are urging people to drink plenty of water, keep cool, take care of others and have a plan over the weekend.

Ahead of the expected sweltering days to come, police have reminded people of the dangers of leaving kids, the elderly and pets unattended in cars.

"There is one golden rule which should never be broken: never ever leave babies, children, the elderly or animals alone in a car even if the air-conditioner is on," deputy commissioner Mark Murdoch said in a statement.

"It doesn't take long for the temperature inside the car to soar, and for the effects of the heat to take hold."

Police also warned people to beware of the dangers of drinking and staying out in the sun in high temperatures.